• Tuberculosis and Respiratory Diseases
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• v.55 no.1
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• pp.21-30
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• 2003

Background : Mucin synthesis in airways has been reported to be regulated by the epidermal growth factor receptor (EGFR) system. Epidermal growth factor receptor transactivation was identified as a critical element in G-protein-coupled receptors (GPCRs)-induced mitogenic signaling. EGF receptor transactivation by G-protein-coupled receptors requires metalloproteinase cleavage of proHB-EGF. This study was hypothesized that lipopolysaccharide (LPS)-induced mucin production associates with epidermal growth factor receptor transactivation, and MUC5AC production associates with epidermal growth factor receptor transactivation by G-protein-coupled receptors that regulates by metalloproteinase. Method : MUC5AC mucin production was examined in NCI-H292 cells and MUC5AC protein synthesis was assessed using ELISA. For the evaluation of mechanism of LPS-induced MUC5AC production, $TNF{\alpha}$ was measured using ELISA with or without pretreatment of heterotrimeric G-protein inhibitor, mastoparan. MUC5AC protein was measure with pretreatment of polyclonal $TNF{\alpha}$ antibody or mastoparan on LPS-induced MUC5AC production. For the evaluation of relation of G-protein and MUC5AC production, G-protein stimulant, mastopara-7, or matrix metalloproteinase, ADAM10, was added to NCI-H292 cells. MUC5AC protein was measure with pretreatment of polyclonal EGF antibody on mastoparan-7-induced MUC5AC production. Results : LPS alone did not increase significantly MUC5AC production. LPS with $TNF{\alpha}$ induced dose-dependently MUC5AC production in NCI-H292 cells. LPS increased dose-dependently $TNF{\alpha}$ secretion, which was inhibited by mastoparan. LPS with $TNF{\alpha}$-induced MUC5AC production was inhibited by neutralizing polyclonal $TNF{\alpha}$ antibody, mastoparan or AG 1472. Mastoparan-7 or ADAM10 increased dose-dependently MUC5AC production, which was inhibited by polyclonal neutralizing EGF antibody. Conclusion : In LPS-induced MUC5AC synthesis, LPS causes $TNF{\alpha}$ secretion, which induces EGFR expression. EGFR tyrosine kinase phosphorylation result in MUC5AC production. EGF-R transactivation by G-protein-coupled receptors requires matrix metalloproteinase cleavage of proHB-EGF.

• Radiation Oncology Journal
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• v.21 no.3
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• pp.227-237
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• 2003

Purpose: The human chronic myelogenous leukemia cell line, K562, expresses the chimeric bcr-abl oncoprotein, whose deregulated protein tyrosine kinase activity antagonizes via DNA damaging agents. Previous experiments have shown that nanomolar concentrations of herbimycin A (HWA) coupled with X-irradiation have a synergistic effect in inducing apoptosis in the Ph-positive K562 leukemia cell line, but genistein, a PTK inhibitor, is non selective for the radiation-induced apoptosils on $p210^{bcr/abl}$ protected K562 cells. In these experiments, the cytoplasmic signal transduction pathways, the Induction on a number of transcription factors and the differential gene expression in this model were investigated. Materials and Methids: K562 cells in the exponential growth phase were used in this study. The cells were irradiated with 0.5-12 Gy, using a 6 Mev Linac (Clinac 1800, Varian, USA). Immediately after irradiation, the cells were treated with $0.25/muM$ of HMA and $25/muM$ of genistein, and the expressions and the activities of abl kinase, MAPK family, NF- kB, c-fos, c-myc, and thymidine kinase1 (TK1) were examined. The differential gene expressions induced by PTK inhibitors were also investigated. Results: The modulating effects of herbimycin A and genistein on the radiosensitivity of K562 cells were not related to the bcr-abl kinase activity. The signaling responses through the MAPK family of proteins, were not involved either in association with the radiation-induced apoptosis, which is accelerated by HMA, the expression of c-myc was increased. The combined treatment of genistein, with irradiation, enhanced NF- kB activity and the TK1 expression and activity. Conclusion: The effects of HMA and genistein on the radiosensitivity on the K562 cells were not related to the bcr-abl kinase activity in this study, another signaling pathway, besides the WAPK family responses to radiation to K562 cells, was found. Further evaluation using this model will provide valuable information for the optional radiosensitization or radioprotection.

• Tuberculosis and Respiratory Diseases
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• v.66 no.4
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• pp.280-287
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• 2009

Background: The epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs), became an attractive therapeutic option for advanced non-small-cell lung cancer (NSCLC). Several studies suggested that there might be some different efficacy or response predictors between gefitinib and erlotinib. We compared the efficacy and toxicity of gefitinib and erlotinib in Korean patients with advanced NSCLC and evaluated specific predictors of response for both gefitinib and erlotinib. Methods: We collected the clinical information on patients with advanced NSCLC, who were treated with gefitinib or erlotinib at the Ewha Womans University Hospital, between July 2003 and February 2009. Median survival times were calculated using the Kaplan-Meier method. Results: Eighty-six patients (52 gefitinib vs. 34 erlotinib) were enrolled. Patient median age was 64 years; 53 (62%) subjects were male. Out of the 86 patients treated, 83 received response evaluation. Of the 83 patients, 35 achieved a response and 12 experienced stable disease while 36 experienced progressive disease, resulting in a response rate of 42% and a disease control rate of 57%. After a median follow-up of 502 days, the median progression-free and overall survival time was 129 and 259 days, respectively. Comparing patients by treatment (gefitinib vs erlotinib), there were no significant differences in the overall response rate (44% vs. 39%, p=0.678), median survival time (301 days vs. 202 days, p=0.151), or time to progression (136 days vs. 92 days, p=0.672). Both EGFR-TKIs showed similar toxicity. In a multivariate analysis using Cox regression model, adenocarcinoma was an independent predictor of survival (p=0.006; hazard ratio [HR], 0.487; 95% confidence interval [CI], 0.292-0.811). Analyses of subgroups did not show any difference in response predictors between gefitinib and erlotinib. Conclusion: Comparing gefitinib to erlotinib, there were no differences in the response rate, overall survival, progression-free survival, or toxicity. No specific predictor of response to each EGFR-TKI was identified.

• Clinical and Experimental Pediatrics
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• v.52 no.1
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• pp.119-123
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• 2009

Renal cell carcinoma (RCC) arising from epithelial cells of the renal tubules is a highly aggressive and malignant tumor in all ages; however, it rarely occurs in children. the standard treatment for RCC is radical nephrectomy with lymph node dissection when the tumor is localized and can be completely resected. Adjuvant chemotherapy, radiotherapy, and immunotherapy are used for pediatric patients with advanced RCC involving lymph nodes or metastatic lesions. Sorafenib is an oral, multikinase inhibitor that has recently been approved for use in metastatic RCC. Common toxicities that have been reported include dermatologic changes such as rash or desquamation and hand-foot skin reaction, diarrhea, fatigue, alopecia, and hypertension. In particular, hand-foot syndrome (HFS) an erythematous skin lesion of the palms and solesis most often caused by cytostatic chemotherapeutic agents. In this report, we have studied a 14-year-old female patient with hand-foot syndrome that occurred in association with sorafenib for the treatment of metastatic RCC. Furthermore, this case demonstrates that reversal of complications can be achieved by discontinuing the drug and intervention with topical steroids, vitamin E, and high-dose pyridoxine.

• Journal of Life Science
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• v.16 no.4
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• pp.589-597
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• 2006

Genistein, a natural isoflavonoid phytoestrogen, is a strong inhibitor of protein tyrosine kinase and DNA topoisomerase activities. There are several studies documenting molecular alterations leading to cell cycle arrest and induction of apoptosis by genistein as a chemopreventive agent in a variety of cancer cell lines; however, its mechanism of action and its molecular targets on human bladder carcinoma and leukemic cells remain unclear. In the present study, we have addressed the mechanism of action by which genistein suppressed the proliferation of T24 bladder carcinoma and U937 leukemic cells. Genistein significantly inhibited the cell growth and induced morphological changes, and induced the G2/M arrest of the cell cycle in both T24 and U937 cells with a relatively stronger cytotoxicity in U937. The G2/M arrest in T24 cells was associated with the inhibition of cyclin A, cyclin B1 and Cdc25C protein expression without alteration of tumor suppressor p53 and cyclin-dependent kinase (Cdk) inhibitor p21(WAF1/CIP1). However, the inhibitory effects of genistein on the cell growth of U937 cells were connected with a marked inhibition of cyclin B1 and an induction of Cdk inhibitor p21 proteins by p53-independent manner. These data suggest that genistein may exert a strong anticancer effect and additional studies will be needed to evaluate the different mechanisms between T24 and U937 cells.

• Journal of Life Science
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• v.21 no.1
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• pp.141-145
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• 2011

Actinomycin D is a natural antibiotic that is used in anti-cancer chemotherapy and is known as a transcription inhibitor. Interestingly, actinomycin D induces phosphorylation of signal transducers and activators of transcription 3 (STAT3) in renal cancer Caki cells. In this study, we examined the molecular mechanism of actinomycin D-induced STAT3 phosphorylation. Treatment with actinomycin D induced phosphorylation of STAT3 (Tyr705) in a dose- and time-dependent manner. However, actinomycin D did not induce phosphorylation of STAT3 (Ser727), STAT1 (Tyr701) and STAT1 (Ser727). Moreover, actinomycin D-induced STAT3 phosphorylation was caused by decreased protein and mRNA levels of SOCS3, but not by JAK2 and SHP-1. In addition, other transcription inhibitor (5,6-dichloro-1-b-D-ribofuranosyl benzimidazole; DRB) also induced phosphorylation of STAT3 (Tyr705). Taken together, the present study demonstrates that transcriptional inhibitors (actinomycin D and DRB) induce phosphorylation of STAT3 (Tyr705) in Caki cells by down-regulation of SOCS3.

• Journal of Life Science
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• v.12 no.2
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• pp.164-172
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• 2002

Breast cancer cell lines display a wide variety of growth factor receptors, and considerable evidences implicate the importance of signalings from those receptors. A useful prognostic indicator would be the level of activity of a second messenger protein used in common by these receptors. Our studies were designed to obtain preliminary information on the possible role of polyamine as a mediator of the membrane-associated protein phosphorylation and as a regulator of second messenger in mitogenic signal of estrogen or growth factors in MCF-7 human breast lancer cells. DFMO significantly inhibited the phosphorylation induced by $E_2$, TGF-$\alpha$ and EGF in membrane-associated proteins (154, 134, 116, and 104 kDa). Exogenous polyamines abolished the inhibitory effect of DFMO. Tyrosine phosphorylations of membrane-associated proteins were not increased by $E_2$ or growth factor treatments and not affected DFMO treatment. Polyamine administration markedly enhanced the tyrosine phosphorylation of membrane-associated proteins (154, 134, and 116 kDa). In the present study, $E_2$ and TGF-$\alpha$ and EGF enhanced protein phosphorylation in the almost same levels. These data indicate that $E_2$ and growth factor signaling pathway may cross-talk through various protein kinase which phosphorylated many substrate proteins (154, 134, 116 and 104 kDa). Polyamines may be involved in growth signaling pathway of $E_2$ and TGF-$\alpha$ or EGF for the cross-talk through regulation of the protein phosphorylation such as 154, 134, 116 and 104 kDa. Polyamine may also selectively interfere with several different protein kinases, and the specific steps in signal transduction system were effected by polyamines.

• Korean Journal of Clinical Laboratory Science
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• v.47 no.3
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• pp.125-131
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• 2015

The discovery of activating mutations in EGFR in a subset of lung adenocarcinomas was a major advance in our understanding of lung adenocarcinoma biology, and has led to groundbreaking studies that have demonstrated the efficacy of tyrosine kinase inhibitor therapy. Cytologic specimen procedures have become increasingly popular for obtaining diagnostic material in lung carcinomas. However, frequently the small amount of material or sparseness of tumor cells obtained from cytologic preparations limit the number of specialized studies, such as mutation analysis, that can be performed. In this study we used microdissection to isolate small numbers of tumor cells to assess for EGFR mutations from 76 cytological smear slides of patients with lung adenocarcinomas. We compared our results with previous molecular assays that had been performed on either surgical or cytology specimens as part of the patient's initial clinical work-up. Not only were we able to detect the identical EGFR mutation through the pyrosequencing, but we were also able to consistently detect the mutation from as few as 25 microdissected tumor cells. Furthermore, isolating a purer population of tumor cells resulted in increased sensitivity of mutation detection as we were able to detect mutations from microdissection-enriched cases. Therefore, microdissection can not only significantly increase the number of lung adenocarcinoma patients that can be screened for EGFR mutations, but can also facilitate the use of cytologic samples in the newly emerging field of molecular-based personalized therapies.

• Tuberculosis and Respiratory Diseases
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• v.58 no.5
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• pp.473-479
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• 2005

Background : Gefitinib targets the epidermal growth factor receptor r(EGFR), and Gefitinib has antitumor activity in patient with non-small cell lung cancer (NSCLC). However, only 10 to 20 percent of patients show a clinical response to this drug, and the molecular mechanisms underlying patient sensitivity to gefitinib are unknown. PTEN (Phosphatase and tensin homolog deleted on chromosome Ten) plays a role for the modulation of the phosphatidylinositol 3-kinase pathway (PI3K), which is involved in cell proliferation and survival, so that it can inhibit cell cycle progression and induce G1 arrest. Therefore, we analyzed the relationship between PTEN expression and gefitinib's responsiveness in patients having advanced non small cell lung cancer that had progressed after previous chemotherapy. Methods : The expression of PTEN was studied by immunohistochemistry in paraffin-embedded tumor blocks that were obtained from 22 patients who had been treated with gefitinib from JAN, 2001 to AUG. 2004. For the evaluation of the relationships between the PTEN expression, the clinical stage and the basal characteristics, those cases that showed the respective antigen expression in >50% of the tumor cells were considered positive. Results : The positive rate of PTEN staining was 55% of the total of 22 patients. There was a significant relationship between the increased expression of PTEN and the response group (p=0.039). However, there was no significant relationship between the expression of PTEN and other clinicopathologic characteristics. Conclusion: The expression of PTEN in patients with advanced non small cell lung cancer that has progressed after previous chemotherapy may play a role in gefitinib's responsiveness.

• Tuberculosis and Respiratory Diseases
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• v.57 no.2
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• pp.160-168
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• 2004

Background : The role of second-line chemotherapy in the treatment of advanced non-small cell lung cancer (NSCLC) is known to be limited. Recently, ZD1839, the small molecule epidermal growth factor receptor-tyrosine kinase inhibitor, has been developed and has shown anti-tumor activity in patients with solid malignant tumors including lung cancer. We evaluated the response rate and toxicities of ZD1839 in patients with advanced NSCLC which has progressed after previous chemotherapy. Patients and Methods : We examined 83 patients with advanced NSCLC treated with ZD1839 for more than 1 month in Korea Cancer Center Hospital during the period from January 2002 to September 2003. All the patients were enrolled in the international expanded access program (EAP) with ZD1839 by AstraZeneca. The administered dose of ZD1839 was 250 mg once daily. Chest radiography and laboratory tests were followed-up. We evaluated the response rate, median survival, and toxicity after treatment. Results : Median age of the patients was 59 years (range 33-76). The most predominant cell type was adenocarcinoma and the most stage of the patients was IV. ECOG performance status was as follows; grade 0-1 in 10, grade 2 in 42, and grade 3 in 31 patients. Partial response was achieved in 12 patients (14.5%). Median overall survival was 9.2 (range 1.3-21.6+) months and median time to progression was 3.1 (range 1-21.2+) months. The most common adverse effect of ZD1839 was skin eruption which developed in 25 patients (25.8%). Significantly higher response rate and survival was found in patients with adenocarcinoma or good performance status. Conclusion : ZD1839 showed modest activity and tolerable toxicity in the treatment for patients with NSCLC which has progressed after previous chemotherapy.